Lawn mower attachment



Maich 12,' 1940. H PBELL 2,193,712

LAWN MOWER ATTACHMENT Filed July 5, 1938 2 Sheets-Sheet 1 March 12; 1940.

A. H. CAMPBELL LAWN MOWER ATTACHMENT Filed July 5, 1938 2 Sheets-Sheet 2 Patented Mar. 12, 1940 UNITED: STATES PATENT OFFICE LAWN MOWER ATTACHMENT Andrew 11. Campbell, Fountain City, Tenn. Application July 5, 1938, Serial No. 217,597

11 Claims.

This invention relates to an improvement in lawn mowers and more particularly to an attachment for a power'driven lawn mower for cutting weeds and tall grass that may be in a I lawn which is too tail to be cut by a conventional operation and for adoption by the ordinary user of lawn mowers of this type, particularly where such lawn mowers are power driven.

The object of this invention is to simplify the construction of an auxiliary attachment which will cut the weeds and high grass effectively in advance of the main cut of the lawn mower by the reel thereof, which may-be readily attached to any type of power driven lawn mower requiring a minimum of power for operation, the construction being so simplified and improved that it may be manufactured at comparatively small cost which will not add materially to the weight of the lawn mower when applied thereto.

The attachment which is the subject-matter of this invention utilizes a plurality of rotary knives operating approximately in a horizontal ll plane and suitably journaled and'supp'orted for eflicient operation to be driven from the source of power of the mower. Each of these knives is complete in itself for effectively severing the tall grass and weeds at a height of approximately three inches above the ground and which do not require a ledger plate or cutter to perform this cutting operation.

It is preferred, however, that-a guard '-plate or: shield be secured to the frame of the mower above the knives and project forwardly beyond thearea of operation thereof, whereby avoiding 'dangerof injury to persons from-theknives. I

have illustrated a preferred embodiment of this which:

Fig.'- 1 is a perspective view of the attachment invention in the accomp nying drawings, in-

Fig. 3 is an end elevation of the attachment, with the guard removed;

Fig. 4 is a front elevation 'of the same showing the mounting of the driving means for one of the knives;

' 5 is a vertical sectional view partly in elevation showing the mounting and drive of an intermediate shaft and knife;

Fig. 6 is a detail rear elevation, partly in section, showing the clutch arrangement for driving 10 the attachment; and

Fig. 'I is a detail sectional view, partly in elevation, showing the relation of the main and auxiliary cutters.

In Fig. 1, the improved auxiliary cutting attachment is shown applied to a power driven lawn mower of'the revolving blade or reel type. The mower may be of any suitable construction, the one shown in Fig. 1, having a supporting frame I, provided with a pair of spaced traction wheels 2, and a cutting reel 3, adapted to be driven by an internal combustion engine 4, such as a gasoline engine mounted on the upper portionof the frame. The engine 4 usually drives the traction wheels 2 and the cutting reel 3 through a shaft 5 and a train of gearing and clutches which is designed generally by the numeral 6, and controlled in the usual way from a handle structure I of the lawn mower.

The attachment shown includes brackets 8, shown in Figs. 3, 4 and 5, and which are secured to the frame I. of the mower, as by set screws 8. One of these brackets is mounted at each end portion of the lawn mower frame, within the adjacent traction wheel 2.

Extending lengthwise in front of the mower frame is a supporting bar l0, having" its opposite end portions secured to and supported upon the brackets 8 for mounting the attachment on the mower frame. Secured at intervals along the supporting bar I. are shaft journals ll, each of which is formed as a U-clamp and secured to the front face of the supporting bar ID, with its interior receiving orv journallng a supporting shaft ll. Each of the shafts l3 isjmounted in anti-friction bearings above and below the shaft journal il, as indicated at II, which anti-friction bearings are preferably ball bearingsandserve to take the end thrust of the shaft inopposite directions.

' Mounted on the lower end of each" shaft I3 is a knife l5,'which is secured to the 'shaftand rotates therewith, which knife has a cutting edge portion Ii at" opposite endsthereofl'the cutting edges It at opposite ends being on opposite sides other shafts will be driven simultaneously with clutch.

of the center of the knife, so as to cut as the latter is rotated by its supporting shaft. I These cutting edges need extend back from the respective ends of the,knife only a short distance because that is sufficient to cut effectively the tall grass and weeds as the machine is advanced, due to the high speed of rotation. r

For transmitting motion from one to another,

each of the shafts l3 has 'a pulley or pulleys ll thereon connected'by a belt l8 with the next adjacent shaft, the middle one of the three shafts, shown in Fig. 1, having two pulleys ll, one of which receives power from the first shaft and the other of which transmits the power to the third shaft, so that all three shafts rotate at the same speed and in unison.

For driving the knives I5, the first shaft l3 extends upwardly above its pulley l1, into a gear box IE supported by a bracket 20 on the connecting bar 10. Gearing. 2| housed within the gear box [9 connects the shaft [3 with a counter shaft 22, journaled in the gear box l9, preferably in ball bearings designed generally by the numeral 23 with provision for end thrust and adjustment at the set screw 24. The countershaft 22 has a pulley 25 thereon connected by a belt 25 with a pulley 21 loosely journaled on the drive shaft of the mower.- The gear box I9 is preferably enclosed to contain'lubricant for the gears and shaft's.

For controlling the the pulley 21 has a clutch 28 at one side thereof; such"as a cone or friction'clutch, the hub 29 of which is slidably keyed to the shaft 5, acted on by the spring 30 which normally tends to press the same into clutchengagement with the pulley 1.. A yoke 3| is pivoted at 32 to the frame I of the mower, as shown in Fig. 1, and is actuated by an arm 33 mounted on a shaft 34 which extends to the upper end of the mower handle I. The shaft 34 has an operating handle 35 arranged to manipulate the shaft 34 to release the It will be apparent that the power driven lawn mower is operated in the usual way for driving the cutting reel 3 andthe traction wheels 2. Normally the clutch 28 will be engaged "during this operation unless retracted by the yoke 3| upon manipulation of the handle 35 against the tensionof the spring 30.

Motion will be transmitted through the belts I8 and pulleys l1 whereby the knives l5 of the the first one. These should' be driven at relatively high speed but this may be controlled according to the ratio of the several driving connections.

As the machine moves forward in its normal cuttingope'ration, the cutting edges l6 operating at high speed will effectively sever any tall grass or weeds in their paths to a height of approximately three inches, or such that the remainder thereof will be effectively removed by the mower reel 3,'the' relation of the cutters being shown in Fig. '7. These knives are not overlapping and are not synchronized. This would not be possible owing to the fact that the units are driven by belts and not gearedto each other. There is a one-sixty-fourth- ,64) of an inch clearance between' the ends of the cutter blades. I

In order to prevent injury to persons by contact with the knives, a shield 35, as shown in Fig. 1, is supported upon the connecting bar Ill and extends forwardly of the attachment and approximately throughout the width thereof, to points drive of the attachment,-

outside of the cutting area of the knives. This forms an effective shield for the knives without interfering with the normal standing positions of the weeds and tall grass.

I claim:

1. In a lawn mower, the combination with a frame, grass cutting means and power means for driving the grass cutting means, of a plurality of rotary knives, means mounting said knives on the frame for turning movement about approximately vertical axes and spaced above the cutting point of the grass cutting means, and means for driving said knives from the power means of the lawnmower.

2. In a lawn mower, the combination; with a frame, grass cutting means and power means for driving said grass cutting means, of a plurality of rotary knives, shafts carrying said knives at points spaced a substantial distance above the grass cutting means, means 'journaling said shafts on the frame about approximately vertical axes, means connecting said shafts together for joint operation, and means for driving said shafts from the power means of the lawn mower.

3. In a lawn mower, the combination with a frame, grass cutting means and power means for operating said grass cutting means, of a connecting bar secured to the frame, journals carried by said connecting bar at points spaced therealong, shafts rotatably ounted in said journals, each of said shafts carrying a rotary knife on the lower end thereof at points spaced a substantial distance above the grass cutting means, gearing connecting said shafts together for joint operation, and gearing connecting one of said shafts with the power means on the lawn mower for operation thereby. i

4. In a lawn mower, the combination with a frame, grass cutting means and power means for operating saidgrass cutting means, of a connecting bar supported by the frame, a plurality of journals mounted on the connecting bar and spaced at intervals therealong, shafts mounted in said journals for turning movement about approximately vertical axes, a cutting knife carried by the lower end of each shaft at a point spaced above the grass cutting means, driving means connecting the upper ends of the shafts together above the journals for joint operation, a gear box supported on the frame and receiving one of said vertical shafts, a countershaft mounted in the gear box and geared to the last-mentioned vertical shaft, and driving means connecting said countershaft with the power means of the lawn mower.

5. Ina lawn mower, the combination with a frame, grass cutting means, power means for driving said grass cutting means, and a shaft connected respectively with the power means and grass cutting means, of a connecting bar secured to the frame at the front of the mower, a plurality of shafts journaled on said connecting bar at points spaced;therealong at a point spaced above the grass cutting means, rotary knives carried by said shafts at the lower ends thereof, means connecting the upper ends of the shafts together, driving means for said vertical shafts, and clutch means for connecting the drive shaft of the mower with said driving means for operation of the knives therefrom.

6. In a lawn mower, the combination of a supporting structure having an angle bar extending transversely thereof, a plurality of shafts, journals secured to the front face of the angle bar and separate therefrom,- said shafts mounted in said journals about approximately vertical axes and extending above and below the angle bar, rotary knives mounted on the lower ends of said shafts, pulleys mounted on the upper ends of the shafts above the angle .bar, and power means connected with one of the shafts for driving the knives.

' '7. In a lawn mower, the combination with a cutting reel and power means for operating said reel, of one or more rotary knives, means mounting said knives on the lawn mower for turning movement about approximately vertical axes and spaced above and in advance of the lower edge portion of the reel, and means for driving said knives from the power means.

8. In a lawn mower, the combination with a cutting reel and power means for operating said reel, of one or more rotary knives, means mounting said knives on the lawn mower for turning movement about approximately vertical axes and spaced above and in advance of the lower edge portion of the reel, means for driving said knives from the power means, and a guardplate secured to the mower and extending forwardly of the path of movement of the knives at a point spaced a substantial distance thereabove for guarding the knives without interfering with the cutting of weeds thereby.

9. In a lawn mower, the combination with a reel for cutting grass, and means for operating said reel, of'a connecting bar extending trans-' versely of the mower in front of the cutting reel,

a plurality of vertical shafts journaled on the connecting bar for turning movement about approximately vertical axes, -weed cutting knives carried by the lower ends of said shafts, means the cutters.

for driving said shafts from the reel operating means, and a guard plate secured to the connecting bar and extending forwardly therefrom beyond the cutting areas of the knives and spaced a substantial distance thereabove to guard said knives without interfering with the presenting of weeds and grass thereto for-cutting.

10. In a lawn mower, the combination with a frame structure with opposite ends, a cutting reel between said ends, and power means for operating said reel, of a connecting bar extending between said frame ends and supported thereon v above the reel, a plurality of upright shafts journaled on said connecting bar, a rotary cutter carried by each of said shafts in position for free rotation at a point spaced appreciably above the lower edge of the reel, and means for connecting said power means with said shafts for driving the cutters.

11. In a lawn mower, the combination with a frame structure with opposite ends, a cutting reel between said ends, crating said reel, of a connecting bar extending between said frame ends and supported thereon above the reel, said bar having an upright front face, journals separate from the bar and rigidly secured to said face and spaced therealong, an

and powermeans for opupright shaft mounted in each journal and hav- I ANDREW .n. swam-n with said shafts for driving- 

